package com.qihang.util;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

public class AES {
	// 加密
		public static String Encrypt(String sSrc, String sKey) throws Exception {
			if (sKey == null) {
				System.out.print("Key为空null");
				return null;
			}
			// 判断Key是否为16位
			if (sKey.length() < 16) {
				System.out.print("Key长度不是16位");
				return null;
			}
			sKey = sKey.substring(0, 16);
			byte[] raw = sKey.getBytes();
			SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");	//"算法/模式/补码方式"
			IvParameterSpec iv = new IvParameterSpec(sKey.getBytes());	//使用CBC模式，需要一个向量iv，可增加加密算法的强度
			cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
			byte[] encrypted = cipher.doFinal(sSrc.getBytes());

			return new String(Base64.encodeBase64(encrypted), "UTF-8");	//此处使用BAES64做转码功能，同时能起到2次加密的作用。
		}

		// 解密
		public static String Decrypt(String sSrc, String sKey) throws Exception {
			try {
				// 判断Key是否正确
				if (sKey == null) {
					System.out.print("Key为空null");
					return null;
				}
				// 判断Key是否为16位
				if (sKey.length() < 16) {
					System.out.print("Key长度不是16位");
					return null;
				}
				sKey = sKey.substring(0, 16);
				byte[] raw = sKey.getBytes("ASCII");
				SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
				Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
				IvParameterSpec iv = new IvParameterSpec(sKey.getBytes());
				cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
				byte[] encrypted1 = Base64.decodeBase64(sSrc.getBytes("UTF-8"));// 先用Base64解密
				try {
					byte[] original = cipher.doFinal(encrypted1);
					String originalString = new String(original);
					return originalString;
				} catch (Exception e) {
					System.out.println(e.toString());
					return null;
				}
			} catch (Exception ex) {
				System.out.println(ex.toString());
				return null;
			}
		}
}
